The present invention relates to a water vapour relief device of the type incorporated in domestic coffee makers, for heating milk to be added to coffee or simply for heating water for obtaining a cup of camomile, tea or the like.
Apart from the heating function of such water vapour relief devices, same also allow the vapour to be bubbled on the surface of the milk, whereby foam is produced thereon, i.e., a "creamy" coffee is obtained, this being very desireable for most coffee drinkers, once the milk has been added to the coffee.
However, obtaining this foam, with conventional devices, requires a certain skill on the part of the person handling same, i.e., a professional expertise, together with a wish to please the client, these being two conditionings which in practice do not always concur.